Electrical coin tester



p 1968 J. JULLlEN-DAVIN I ELECTRICAL COIN TESTER 6 Sheets-Sheet 1 Filed Dec. 19, 1966 V, w 1 M w A vm L C V LL LL LL J 6 A, r h II Il a .n 4 T m b I. M F N v v r A \\V l lillltl V M '0 L r Q 7 YV i 8 Z a w 2 K P 7, 1968 J. JULLIEN-DAV IN 3,401,780

ELECTRICAL COIN TESTER Filed Dec. 19, 1966 6 Sheets-Sheet 2 P 7, 1968 J. JULLlEN-DAVIN 3,401,780

ELECTRICAL COIN TESTER Filed Dec. 19, 1966 6 Sheets-Sheet 3 III/A i Sept. 17, 1968 6 Sheets-Sheet 4 Filed Dec. 19, 1966 S pf. 17, 9 J. JULLI EN-DAVIN ELECTRICAL COIN TESTER 6 Sheets-Sheet Filed Dec. 19, 1966 United States Patent 3,401,780 ELECTRICAL COIN TESTER Jean Jullien-Davin, Valence, France, assignor t0 Crouzet, Paris, France, a French company Filed Dec. 19, 1966, Ser. No. 602,992 Claims priority, application France, Dec. 31, 1965, 715

9 Claims. (Cl. 194100) ABSTRACT OF THE DISCLOSURE A coin selector having coin-switching means for conveying the coins in either of two directions, two coin-exit channels disposed downstream of said coin-switching means, and test means disposed upstream of said coinswitching means for actuating the latter and comprising means responsive to a variation of impedance produced by a coin to be tested and control means responsive to the motion of each coin to be tested as said coin passes through a test location, so as to actuate said impedance variation responsive means.

This invention relates to a coin selector which is more specifically (although not essentially) intended for slot machines and which provides a solution to the particularly difficult problems involved in the construction of reliable slot machines.

It is known that there are two types of slot machines in existence.

In the first type of machine, the customer is obliged to tender the exact sum required and therefore has to insert in the machine either one or more coins in exact denominations so as to receive in exchange such article as sweets or candy, platform tickets, postage stamps and the like. Some slot machines even return change which is delivered in the same manner as merchandise and which is taken from a stock of coins previously introduced inside the slot machine. In the machines of this type, testing of inserted coins is effected by means of mechanical or electromagnetic selectors according to their geometrical characteristics (diameter, thickness, presence or absence of a central hole, smooth or milled edge), or according to their physical characteristics (nature of the metal, whether magnetic or nonmagnetic) and also according to their weight.

Coin selectors of the known types referred to are not designed to reject improper coins such as foreign currency if such coins have the same diameter, the same thickness and the same weight as the type required by the machine; as a rule, this disadvantage is not considered of paramount importance since slot machine owners are usually prepared to allow a small percentage of loss incurred by fraud.

In another class of slot machine, the customer pays for the merchandise by means of a number of different coins, the sum of which may exceed the price of the merchandise. These machines deliver commodities thus paid for and return change, the amount given back being variable and made up of coins of different values taken from stocks which, while undoubtedly made up of good coins at the outset, are subsequently completed and maintained with coins tendered by previous customers. It is wholly apparent that, in this case, the slot machine owner would in no way be prepared to tolerate acceptance by his machine of any false or illegal coins which may be intro- "ice to vary when a metal coin is placed inside said winding.

Either by virtue of the fact that the coin is formed of a magnetic metal which concentrates the magnetic flux (frequency of the order of 2 to 5 kc./s.).

Or by virtue of the fact that the coin is formed of a nonmagnetic metal which induces losses due to eddy currents and to skin effects (frequency of the order of 25 to kc./s.).

In both cases, the variation of impedance depends on the one hand on the position of the coin inside the winding and, on the other hand, in a predetermined positron on the nature of the metal, on the dimensions of the coin and on the weight distribution (or in other words, in the case of coins made of the same metal and having the same general shape, weight and size, on the distribution of details provided thereon such as surface engravings, portraits and other designs).

The object of the invention is to provide a coin selector based on the above named impedance variation produced by a coin, said selector being simple, easy to manufacture, inexpensive and efiicient in its working.

The foregoing properties of the invention will become apparent from the following detailed description in connection with a number of forms of construction which are illustrated in the accompanying drawings, in which:

FIG. 1 is a diagram of the bridge which is supplied directly from an alternating-current source and in which the reference impedance is a simple adjustable resistor and the amplifier is of the differential or balanced type;

FIG. 2 is a diagram of the bridge which is supplied directly from an alternating-current source and in which the reference impedance is a winding containing a standard coin and the amplifier is of the differential or balanced type;

FIG. 3 is a diagram of the bridge which is supplied with current by means of primary windings, the amplifier being of the nondilferential or unbalanced type;

FIG. 4 is a sectional view along line IVIV of FIG. 5 and shows diagrammatically one example of embodiment of the reference impedance;

4 FIG. 5 is a sectional view along line VV of FIG.

FIG. 6 is a sectional view along line VI-VI of FIG. 7 and shows diagrammatically the arrangement of the apparatus in the case in which the coin to be tested takes up a stable position;

6 FIG. 7 is a sectional view along line VII-VII of FIG.

FIG. 8 is a general diagram of the device corresponding to FIGS. 6 and 7;

FIG. 9 is .an explanatory diagram of operation of the selector;

FIG. 10 shows diagrammatically the arrangement of the apparatus in the case in which the coin passes in uninterrupted motion and temporarily takes up the testing position;

FIG. 11 is a sectional view along lines XI--XI of FIG. 10;

FIG. 12 is a sectional view along the broken line XII XII of FIG. 10;

FIG. 13 is a general diagram of the device corresponding to FIGS. 10, ll and 12, and finally,

FIG. 14 is an explanatory diagram of operation of the selector.

The novel coin selector operates on the principle of variation of impedance which is produced within a winding supplied with alternating current at a suitable frequency as a result of the presence of a metal coin in a well-defined position within the interior of said winding. The apparatus is provided for the purpose of receiving the coin to be tested with at least one so-called measurement winding whose impedance is compared with an adjustable reference impedance, the comparison referred to being effected by means of a Wheatstone bridge shown diagrammatically in FIG. 1. The bridge, which is constituted by stationary resistors R R by the adjustable resistor R and by the winding E is supplied with alternating current at the terminals A and B whilst the measurement voltage is collected at the terminals C and D. A standard coin P which is acknowledged as legal tender is placed in a well-defined position within the winding E and the reactor R is adjusted so that said voltage is zero; subsequently, if any coin P which is substituted for the coin P should fail to reduce the output voltage to zero, that coin will accordingly be deemed unacceptable and automatically discarded. To this end, the voltage developed across the terminals C and D is applied to an amplifier G which is necessarily of the differential or balanced type inasmuch as neither of the points C and D can be maintained at a fixed potential by virtue of the direct coupling of the bridge with the supply circuit. In view of the fact that the resistors are not of the same type, the diagram of FIG. 1 sets problems of rotation of phase and compensation for temperature effects.

FIG. 2 represents a more advantageous diagram. In this case, the reference impedance is constituted by a winding E which is identical with E and in which a standard coin P is placed permanently. The two resistors R R are the two halves of the single resistor of a potentiometer, the sliding contact D of which constitutes the output terminal of the bridge. The mobility of the sliding contact D makes the bridge adjustable; symmetry between E, E and R R removes the disadvantages arising from rotation of phase and influence of temperature. The amplifier G necessarily remains of the differential or balanced type.

FIG. 3 shows an advantageous mode of execution of the bridge which makes it possible to maintain one of the output terminals at a fixed potential by means of a connection to ground (earth), thereby permitting the use of an amplifier of a simpler design which does not therefore have to be of the differential type. Voltage is applied to two parallel-connected primary windings E E of two transformers 1 and 2, the windings E E of which constitute respectively the secondaries; since the bridge proper is no longer directly connected to the supply, one of its terminals (such as C, for example) can be connected to ground; the other adjustable terminal D is connected to the amplifier 3.

It is apparent that a number of different combinations can be adopted for the purpose of forming a Wheatstone bridge without thereby departing from the scope of this invention. It will be assumed in the remainder of the description that the bridge is designed according to the diagram of FIG. 3.

FIGS. 4 and 5 show one nonlimitative example of the transformer 2 and of the device which serves to maintain the standard coin P in a predetermined position.

The primary and secondary windings E E are supported by a hollow insulating coil former 2 of rectangular cross-section (as shown in FIG. 5) between flanges 2a. The standard coin P is maintained in a well-defined position which is adjustable in the longitudinal direction and without lateral play inside the winding E by means of a V-shaped sliding member 4 and a second sliding member 4' which has an inclined surface 4a. The members 4 and 4' are maintained applied against the coin P by means of screws 5 and 6. The members 4, 4', 5 and 6 are formed of non-metallic and non-magnetic material.

FIGS. 6 and 7 show by way of nonlimitative example one arrangement of the selector in which the coin to be tested is brought into a fixed position.

The primary and secondary windings E B are supported between flanges 1a by a hollow insulating former 1 having a rectangular cross-sectional configuration and disposed vertically. A duct 7 of rectangular cross-section for conveying the coin to be tested is mounted above the former 1 and formed of nonmetallic and nonmagnetic material. There is placed beneath the former 1 a component 8 made of nonmagnetic material and providing two passageways or ducts 8a and 8b which are oriented in two different directions; a pin 9 which is carried by the moving armature 10 of an electromagnet 11 is placed inside the duct 8a and a pin 12 carried by the moving armature 13 of an electromagnet 14 is placed inside the duct 8b. When a coin P is introduced, said coin comes to rest against the stops 9 and 12 in a stationary position; it is in this position that the comparison operation will take place. This operation is permitted when the coin P cuts off the light beam which is emitted by an electric light bulb and which normally passes through the aperture 1b so :as to illuminate a photodiode 16. The comparison operation is carried out after a given time-delay which permits the coin to reach its stable position and also permits the damping of any possible rebounding of the coin against the stops 9 and 12.

If the coin is accepted as conforming to the standard coin, the electromagnet 11 is accordingly energized, its armature 10 pivots about its pin 10:: and retracts the stop 9, thus allowing the coin to fall into the duct 8a through which it is conveyed to the stock of good coins; as this coin passes, it masks the aperture through which a lamp 17 continuously shines on a photodiode 18. The beam being thus interrupted results in the delivery of a pulse which initiates the return of the electromagnet 11 to the inoperative position, returns the stop 9 to its initial position and restores the apparatus to a state of readiness for testing another coin. At the same time, the pulse controls the registering of the coin in a counter or in an automatic accounting unit.

On the contrary, if the coin fails to conform to the standard coin and is therefore unacceptable, it is the electromagnet 14 which is in that case energized; the armature 13 of said electromagnet pivots about its pin 13a, retracts the stop 12, thereby allowing the coin to fall into the duct 8b and to be directed therein to a discharge trough in which it can be recovered by the customer. As it passes, the coin masks the aperture 8d, and, by virtue of the photodiode 19 which is associated with the lamp 20, generates a pulse which initiates the return of the electromagnet 14 to the inoperative position and may if necessary cause a counter to progress by one unit if it is desired to keep a statistical record of rejected coins.

Finally, if either a good or a bad coin were to remain inside the apparatus for any reason such as the development of a fault condition or a failure of the supply circuit, the user would be able in such a case to press a push-button 21, the control rod 21a of which would accordingly actuate the arm 13b of the armature 13 and initiate the withdrawal of the stop 12, thereby making it possible to direct the coin towards the discharge trough and return it to the customer. This arrangement does not exclude the additional safety measure which consists in making provision in the zone 22 for known preselection means located in the duct 7 upstream of the apparatus. Such means can consist in particular of a calibrated slot which prevents the introduction of coins which are either bent, twisted or have dimensions which are greater than those of the standard coin, such coins being otherwise liable to jam inside the apparatus.

The operation of the selector will become wholly apparent from FIGS. 8 and 9, in which the same reference numerals have been assigned to elements already described. An alternating-current signal is collected at the output terminal D of the Wheatstone bridge E E R R (FIG. 3). Said signal is amplified by the amplifier 3, then applied to a detector 23 which delivers a directcurrent signal, the voltage of which is dependent on the amplitude of the alternating-current signal. The detector 23 controls a threshold shaping-trigger 24 of known type which delivers at its output either a signal Q representing the logic value one or its complement 5 representing the logic value zero, depending on whether the input level is very close to zero or on the contrary very different from zero. The signal Q is characteristic of a zero voltage at terminal D (bridge in a state of equilibrium), that is to say of an aceptable coin; the signal is characteristic of a voltage which is different from Zero at terminal D (bridge in a state of unbalance), namely which is characteristic either of the absence of a coin or of the presence of an unacceptable coin. The signal 2 or E5 is applied on the one hand to an AND gate 25 and, on the other hand, through a switching unit 27, to an AND gate 26, with the result that the gate 26 always receives the signal which is complementary to that which is received by the gate 25. When the light beam which is sent out from the lamp is intercepted by the coin P, the photoelectric cell 16 is no longer conductive. This change of state actuates a shaping trigger 28 which trips a monostable element 29 and this latter in turn delivers a pulse to two AND gates 25 and 26 after a predetermined time interval. That gate 'which is energized by the signal g delivered by the trigger 24 becomes operative and transmits the pulse whilst the other gate which receives the signal 5 remains inoperative.

If the coin is found to be acceptable, the gate 25 is accordingly openative and transmits a pulse which is amplified by an amplifier 30 to a bistable device 31 which changes its state and initiates the supply of current to the electromagnet 11 so as to withdraw the stop 9; the coin accordingly falls into the duct 8a and is directed therein to the stock of good coins.

As it passes, the good coin referred-to masks the aperture -8c, with the result that the photodiode 18 is no longer conductive and actuates the shaping trigger 32 which emits a pulse, one effect thereby produced being to restore the bistable device 31 to its initial state, to de-energize the electromagnet 11 and to return the stop 9 to its initial position and another effect thereby produced being to initiate the progression by one unit of a summation counter 33 which forms part of an automatic accounting unit.

If, on the contrary, the coin received is found to be unacceptable, the trigger 24 delivers the signal 5 and, in this case, it is the gate 26 which receives the complementary signal x by means of the switching unit 27 and accordingly becomes operative. Thus, the pulse of the monostable element 29 is transmitted by the amplifier 34 to the bistable device 35 which, as it changes state, energizes the electromagnet 14 and withdraws the stop 12. The coin is then directed into the passageway 8b and, as it passes, masks the aperture 8d, with the result that a pulse produced by the photodiode 19 and delivered through the trigger 36 is applied to the bistable device 35 which reverts to its initial state, interrupts the supply to the electromagnet 14 and replaces the stop 12 in position.

FIG. 9 is a diagram which shows as a function of time the nature of the signals emitted by the elements 24, 16, 28 and 29. At the time t no coin is present, the bridge is in a state of unbalance, the signal has the level indi cated by the full-line curve; the coin then approaches the test position and, at the time t prevents the exciting light beam from falling on the photodiode 16 which accordingly trips the element 29. Thereupon, the coin reaches the stops 9 and 12 and, after rebounding thereon, remains in a stable position (full-line curve if the coin is acceptablewhich corresponds to the signal xdotted-line curve if the coin is unacceptablewhich corresponds to the signal 5). After a time-delay r, at the time the coin is discharged either in one direction or in the other; at the time t the coin no longer intercepts the light beam which excites the photodiode 16.

In the device shown in FIGS. 6, 7 and 8, there remains a possibility which, although remote, is nevertheless not negligible. This is that a substandard coin which may, for example, be smaller than the normal size may take up a different stable position against the stops 9 and 12 and thus be located precisely in the required position to give a zero signal at the output of the bridge, taking into account the different nature of the metal. This danger is removed in the alternative form described hereunder with reference to FIGS. 10, 11 and 12, which show by way of nonlimitative example the arrangement of a preferred variant of the selector wherein the coin to be tested passes inside the test winding in uninterrupted motion, provision being made for means consisting of a photodiode associated with an electric light bulb whereby the comparison operation is permitted only at the precise instant when the coin takes up in a transient manner the exact position required for the testing operation. This arrangement permits the use of logic circuits of simpler design than in the previous embodiment.

In the figures referred-to above, elements which continue to perform the same functions as in the previous embodiments again bear the same reference numerals.

In the alternative form now under consideration, three ducts of rectangular cross-sectional configuration are provided for guiding coins and are disposed in coextensive relation in a vertical plane and in oblique alignment,

viz:

An inlet duct 7 which can usefully be provided in the zone 22 with known preselection means such as, in particular, a calibrated slot for preventing any insertion of coins which are either bent, twisted or of larger dimensions than those of the standard coin and which might otherwise be liable to jam inside the machine;

A duct formed in a nonmagnetic insulating transformercoil former 1 provided with flanges 1a for accommodating the test Winding E and the primary supply winding E An elongated slot 1b is provided in the coil former upstream of the winding E in order that the light beam emitted by a lamp 15 can pass therethrough to a photodiode 16, said photodiode being supported by a collar 36 (FIG. 11) which can be positionally adjusted in a longitudinal direction;

A duct 8 of rectangular cross-section comprising a direct passageway 8a for directing acceptable coins and a branch passageway 8b for directing unacceptable coins; access to the passageway 8b is normally possible but can be prevented by means of a shutter 9 which is secured by means of arms 9a to the moving armature 10 of an electromagnet 11; when the electromagnet 11 is energized, the shutter 9 ensures continuity in the direction of the passageway 8a (FIG. 12); in the open position, an arm 9b of the shutter 9 is inserted in the passageway 8a, thereby preventing unacceptable coins from being accidentally conveyed further in this direction.

An aperture which is located downstream of the shutter 9 is intended to permit a light beam emitted by a lamp 17 to pass through said aperture and to shine on a photodiode 18, these two elements being mounted in the abovementioned collar 36; as acceptable coins pass through and intercept the light beam, a pulse is thereby produced and the apparatus is set in a condition of readiness for testing another coin and initiating the progression by one unit of a summation counter or actuating an automatic accounting device.

FIGURE 13 provides an explanatory illustration of the mode of operation. There are again shown in this figure, as in FIG. 8, the bridge E E R R wherein the signal delivered at the terminal D of said bridge controls the chain comprising the amplifier 3, the detector 23, the threshold shaping-trigger 24 so as to apply at one of the inputs of the AND gate 25 a signal x which is characteristic of an acceptable coin (bridge in a state of equilibrium) or a signal E which is characteristic either of the absence of a coin or of the presence of a faulty coin (bridge in a state of unbalance). As soon as the coin has intercepted the light beam from the lamp 15 and again permits the illumination of the photodiode 16, a pulse is delivered from said photodiode through the trigger 28 to the gate 25. I n the presence of the signal x (acceptable coin), the gate 25 is in the operative state and transmits the pulse which is amplified by the amplifier 30 to the bistable device 31 which accordingly trips, energizes the electromagnet 11 and closes the shutter 9, thereby ensuring continuity of the duct 8 with the passageway 8a in order to convey the coin to the stock of acceptable or good coins.

As it passes, the acceptable coin masks the aperture 8c; the lamp 17 no longer shines on the photodiode 18 which accordingly delivers a pulse via the trigger 32 on the one hand to the bistable device 31 which reverts to its initial state, interrupts the supply to the electromagnet 11 and thus replaces the shutter 9 in the open position and, on the other hand, to the summation counter 33 which forms part of an automatic accounting unit.

In the presence of the signal (unacceptable coin), the gate 25 remains inoperative, and shutter 9 remains open and the coin falls directly through the passageway 8b into the discharge trough of the slot machine.

It should be noted that, in this arrangement, the customer is not required to perform any manual operation in order to recover either a good or bad coin in the event of failure of the machine, whatever the cause of such failure.

FIG. 14 is a diagram which shows as a function of time the nature of the signals emitted by the elements 24, 16, 28 and which clearly brings out the enhanced responsiveness of the machine as achieved in this alternative form of execution in comparison with the previous arrangement.

The curve which is shown as a chain-dotted line represents the level of the signal emitted by the trigger 24 when no coin is present (bridge in the state of unbalance); when a coin is inserted at the time t said coin modifies the signal as it passes through the winding. For example, the full-line curve and the broken-line curve represent the signals of two coins which are nearly identical such as, for example, two coins having the same value but bearing different dates of issue and both of which must be accepted; the chain-dotted curve is that of a different coin which has to be rejected.

At the time t the coin interrupts the illumination of the photodiode 16, then restores said illumination at the time t and initiates the pulse which permits the testing of a coin, the times and t being adjustable by longitudinal displacement of the sliding collar 36. At the time t the two adjacent curves are located at a level corresponding to the signal x (characteristic of acceptable coins); the corresponding coins will be accepted; the coin corresponding to the chain-dotted curve will be rejected.

If the value t is set to a shorter time (for example t it is apparent that only the coin corresponding to the full-line curve will be accepted.

If I is set to a longer time (for example t it is in that case apparent that only the other coin corresponding to the chain-dotted curve will be accepted.

I claim:

1. In a coin selector which is intended to separate good coins from bad coins and comprising an admission channel for guiding coins to be selected, coin-switching means disposed downstream of said admission channel for conveying the coins in either of two directions according as said coins are good or bad, two coin-exit channels disposed downstream of said coin-switching means, and coin-testing means disposed upstream of said coin-switching means for testing coins and for actuating said coinswitching means according to the result of the test, said coin-testing means comprising, on the one hand, at least a Wheatstone bridge responsive to a variation of impedance produced by a coin to be tested, said bridge having a first arm constituted by an impedance measuring winding which can be supplied with alternating current of constant frequency and which is disposed around the coin-admission channel through which each coin to be tested must pass, a second arm connected in series with the first and forming a reference impedance, a thirdand fourth arm each constituted by a resistor, at least one of the second, third and fourth arms of the bridge being adjustable, and on the other hand, coin motion responsive control means responsive to the passing of each coin to be tested through a test location in the measurement winding of the bridge, so as to actuate said Wheatstone bridge at the moment when said coin passes through said test locations, whereas said coin-swiching means comprises a detector connected to said bridge, a threshold trigger coupled to said detector, a first AND gate connected directly to said threshold trigger, a switching unit connected to said threshold trigger, a second AND gate connected to said switching unit, both gates being connected to said control means so that said AND gates are actuated by said control means when a coin passes through the test location, and electromagnetic retaining means disposted in the two coin-exit channels for switching coins, said retaining means being connected to said AND gates so as to be controlled by said gates.

2. A coin selector as claimed in claim 1 additionally comprising a trigger followed by a monostable time-delay element disposed between the motion responsive control means and the AND gates.

3. A coin selector as claimed in claim 1 further comprising bistable devices for resetting to the operating position after the selection of a coin, said bistable devices being disposed between the AND gates and the electromagnetic retaining means for the purpose of controlling said retaining means, means for indicating the transfer of coins and disposed in the coin-exit channels downstream of the electromagnetic retaining means, and shaping triggers interposed between said coin motion responsive control means and said bistable devices.

4. A coin selector as claimed in claim 3, wherein the reshaping trigger corresponding to the exit channel for the discharge of accepted coins is operatively connected with counting means.

5. In a coin selector which is intended to separate good coins from bad coins and comprising an admission channel for guiding coins to be selected, coin-switching means disposed downstream of said admission channel for conveying the coins in either of two directions according as said coins are good or bad, two coin-exit channels disposed clownstream of said coin-switching means, and cointesting means disposed upstream of said coin-switching means for testing coins and for actuating said coinswitching means according to the result of the test, said coin-testing means comprising, on the one hand, at least a Wheatstone bridge responsive to a variation of impedance produced by a coin to be tested, said bridge having a first arm constituted by an impedance measuring winding which can be supplied with alternating current of constant frequency and which is disposed around the coin-admission channel through which each coin to be tested must pass, a second arm connected in series with the first and forming a reference impedance, a third and a fourth arm each constituted -by a resistor, at least one of the second, third and fourth arms of the bridge being adjustable, and, on the other hand, coin motion responsive control means responsive to the passing of each coin to be tested through a test location in the measurement winding of the bridge, so as to actuate said Wheatstone bridge, at the moment when said coin passes through said test location, whereas said coin switching means comprises a detector, a trigger connected to said detector, an AND gate having two inputs one of which is connected to said trigger, whereas the second input of said AND gate is connected to the coin motion responsive control means, a bistable device connected to the output of said AND gate, electromagnetic coin-switching means for controlling the opening of the exit channel for the discharge of good coins, means for indicating the transfer of good coins, a reshaping trigger connected to said indicating means for receiving the signals delivered by said indicating means and also connected to said bistable device for resetting said bistable device in the operating position thereof.

6. A coin selector as defined in claim 5, additionally comprising a counter for counting good coins and connected to said reshaping trigger.

7. A coin selector as claimed in claim 3, additionally comprising amplifier means disposed between the Wheatstone bridge and the detector and another amplifier means disposed between each AND gate and the corresponding bistable device.

8. A coin selector as claimed in claim 1, wherein the coin motion responsive control means comprises a light source for producing a light beam which can be intercepted by said coin and means responsive to said light beam and connected to said AND gates.

9. A coin selector as claimed in claim 3, wherein the means for indicating the transfer of coin-s which have References Cited UNITED STATES PATENTS 1,910,963 5/1933 Polsen et al. 194100 3,059,749 10/1962 Zinke 194-100 10 3,152,677 10/1964 Phillips 194100 FOREIGN PATENTS 11/ 1936 Great Britain.

3/1951 Belgium.

SAMUEL F. COLEMAN, Primal Examiner. 

